Tumbler lock and key therefor



Nov. 17, 1931. J. A. MUZZIO TUMBLER LOCK AND KEY THEREFOR Filed June ll, 1928 ATT QRN EYS Patented Nov. 17, 1931 UNITED STATES PATENT OFFKCE JAMES A. MUZZIO, OF CLEVELAND, OHIO, ASSIGNOR TO ROSA S. MUZZIO, 0F CLEVELAND, OHIO TUMBLER LOCK AND KEY THEREFOR Application filed June 11,

This invention relates to tumbler locks and to the key therefor, and more particularly to multiple ward locks'and keys where normally it would be possible to insert the key into the lock in several different positions. The object of the invention is to provide a tumbler lock embodying relatively rotatable cylinder and plug members and a key therefor, together with means whereby the key may be inserted into the plug in only one correct position and also may be inserted into andremoved from the cylinder in only the one or more desired positions, thereby to prevent injury either to the locking mechanism or to the key, all as will more fully hereinafter appear.

Further objects of the invention are in part obvious and in part will appear more in detail hereinafter.

In the drawings, which represent one suitable embodiment of the invention, Fig. 1 is a side elevation of the lock with the key inserted thereinto; Fig. 2 is an end view of the lock; Fig. 3 is in part a side elevation and in part a longitudinal section on the line 3-3, Fig. 2, with the key partly inserted; Fig. 4 is a cross section on the line 1- 1:, Fig. 3; Fig. 5 is a detail sectional elevation on approximately the line 55, Fig. 2; Fig. 6 is a detail view of the key; Fig. 7 is an enlarged cross section thereof on the line 77, Fig. 6; and Fig. 8 is an end view.

The present invention has more particular relation to multiple ward locks, or, in other words, locks of the relatively rotatable cylinder and plug type in which a plurality of sets of tumblers are cooperatively associated on cylinder and plug and the key is provided with the necessary number of wards or ribs to actuate the several sets of tumblers. Any suitable tumbler mechanism may be used. but the drawings show a so-called fourway lock of the same form illustrated and described in my prior Patent No. 1,594,297, granted July 27, 1926, to which reference may be had for a more complete description if necessary. The lock illustrated comprises a stationary cylinder 1 in which is a rotatable plug 2, the latter having an opening 3 through its center of cruciform cross section. In the plug are a plurality, four being shown, of

1928. Serial No. 284,515.

sets of lever tumblers 4, located in the slots of the cruciform opening 3 and adapted to be engaged along their inner edges by the wards of the key and to be moved into or out of engagement with a series, four being shown, of longitudinally extending slots 5 in the surface of the opening in the cylinder. The key 6 has a shank or operating end which is cruciform in cross section, as shown in Fig.

7, the edges of its four wards or ribs 7 being curved differently, as at 7 a, on combination principles. The several levers being of different shapes and proportions and the several wards being different, it is apparent that the key will correctly actuate the tumbler levers to release the plug and enable it to be rotated in the cylinder only when the key is inserted into the plug in the correct one of the possible four positions, all according to my prior patent referred to. If the key is inserted in any one of the other three or incorrect positions, it does not properly actuate the tumblers and an attempt to rotate the plug either injures the tumblers or some other part of the lock mechanism or tends to twist or injure the key, and such attempted operation should be prevented. For this pur pose I provide the key and plug with cooperating means to insure introduction of the key into the plug only in the correctposition. The means shown for this purpose comprises a small fiat or fillet 8 lying in the valley between two ribs or wards of the key, which fillet cooperates with an extra recess or space formed by cutting off one of the points or edges of the metal segments lying at the crotch between the parts of the cruciform slot or opening in the plug, as at 9, Fig. 2. Said fillet should extend throughout the full length of the valley, as shown in Fig. 3. or at least must have a portion lying at that end of the key which is first introduced into the lock, so that no introduction of the key into the lock to any extent is possible except in the one correct position where the fillet registers with its recess.

Experience has shown that with such an arrangement it is still possible to insert the key only part way into the plug or to a position short of home. Even a small fracat the 3 oclock, Goclock or 9 tion less than full insertion, say g of an inch, will fail to correctly actuate the tumblers and release the plug. I therefore provide means cooperatively related on the key and cylinder to insure a full insertion. Moreover. with these multiple way locks, such as the four-way lock shown, and according to the device which the rotatable plug actuates, it is desirable that the key be inserted into and removed from the lock as a whole only in certain positions. For example, assuming the four slots in the cylinder to be located at positions corresponding to12, 3, 6 and 9 oclock on the clock dial, and also assuming: that the rotatable plug actuates the bolt of a mortise lock and requires a full 12 hour rotation, it desirable to permit the key to. be inserted into the lock only in the one position permitted by the fillet 8, which we will call the 12 oclock pos tion, and to compel its rotation through 360 and permitits withdrawal only at 12 oclock. position. absolutely preventing any possible withdrawal oclock positions. In these three positions the bolt mechanism of the mortise lock would be neither Fully loc red nor fully released. The cooperating means between the key andcyl inder therefore compels such operation. A 'ain, some locks operate by 180 rotation of the key, so that it is c esirable to permit its insertion and removal at say 12 and 6 cclock positions. respectively.

In the arrangement shown in the drawings, the cylinder and key are provided with cooperating means including a proper obstacle and a gate-way therein to compel proper key operation. The means shown comprises a washer or plate 10 fixed in the cylinder. such as by being a. driving fit therein, and provided with a round key opening 11 hav ng an extension or gate-way 12 at one'side. The inner edge portion forms an obstacle for a proiection. such as a pin 13. upon the shank of the key near its head 14.. Bevond the washer 10 the lock cylinder isprovided with a recess or channel 15. Therefore, assuming the lock to be locked with the tumblers extended into their slots in the cvlinder. the kev can be inserted into the look. only in the posit on shown in Fig. 3, in which the fillet 8 registers with the recess 9 of the plug, and in which the pin 13 registers with the recess or gate-Va 12 in the obstacle. It is inserted fully home to the dotted. line position. Fig. 3. where the pin 13 lies in the channel 15, and in such position may be rotated a full 360 and then withdrawn. As a further guard and. to direct the attention of the operator to proper operation and cause him to: habitually insert the k y properly, the head of the key may be made of special form, so that proper key position can be detected in the dark by the sense of feeling. For example, thehead of the key shown is round but is provided upon one face with a knob or projection 16. By grasping this key with the knob in contact with the finger instead of the thumb, the pin 13 is brought upwardly to the 12 oclock po sition in proper registration with the gateway 12.

Obviously, when 180 rotation is desirable, a second gate-way 12a may be located in the washer 10.

This arrangement insures insertion of the key into both the plug and cylinder in the proper position and prevents attempts to 1'0- tate the key except-in the proper position and therefore avoids injury either to the key or the lock mechanism.

What I claim is 1. A key for cylinder locks, said key having handle and, shank portions, the shank portion being of generally cruciform cross section and provided with a plurality of longitudinally and radially extending wards adaptedto actuate lock tumblers, and a fillet at the advanceend of the key in a valley between two. of itswards, said fillet being adapted. to: prevent introduction of the key into thelock except in a definite position.

2. A key of the character described in claim 1, in which said fillet is of full length and extends. from end to end of the valley in which it lies.

In testimony whereof I hereby aliir; my

signature.

JAMES A. MUZZIO. 

